“˜Isn’t the East Village sort of like Beauty and the Beast in the summer?” Nico Muhly exclaims. “You know, “˜Bonjour, good day, how is your family, how is your wife”‰”¦”‰'”‰” It’s our first outing of several together, and we are walking at typical Nico pace””an excitable, bouncier version of the New York Walk. In the span of three blocks, we have passed four people he knows, including a member of the indie rock band Ratatat, and soon we will be picking up a score from composer Philip Glass, Muhly’s de facto boss, who’s eating dinner at the vegetarian kosher Indian joint Madras.

In Muhly’s world, Houston Street as Disney movie makes sense. His life is an odd fairy tale in which he inhabits several characters at all times. There is, first and foremost, Nico the Composer, who has since age 18 assisted Glass, conducting and editing his film scores, and has also emerged as a star in his own right, with an album of his own work, Speaks Volumes; Nico the Helper to Famous Singers, who “enables” the likes of Björk, Antony, and Rufus Wainwright; and Nico Himself, the sweet, gleeful downtown kid, the 26-year-old Columbia and Juilliard graduate in perpetual motion. That last Nico lives in a Chinatown loft (above a sweatshop”“cum”“mah-jongg parlor), with his cats Duane and Reade and a roommate, Liz, whom he’s known since they were kids.

“There are so many things that are surreal in one’s day,” he says, laughing. “I’ve always lived a little surreal. There’s an impossibility about my childhood that I love.” His mother, an artist named Bunny Harvey, toted him off at age 13 to Rome, where he attended a school “like an actual Fellini movie, with a hunchback gym teacher, a midget art teacher, totally out of control.” Of course, that was nothing compared with a months-long residency in Egypt in first grade. “We just sort of took off,” Muhly says. “I was just like, “˜Okay, we’re goin’ on the archaeological dig.’ And now I’m just like, “˜Okay, goin’ to the ballet.'”

He’s referring to From Here on Out, the piece he’s scored for fellow young up-and-comer Benjamin Millepied, premiering October 26 during American Ballet Theatre’s City Center season. Millepied first heard about Muhly from friends at Juilliard and was immediately taken with his music; Muhly was equally enamored of Millepied’s choreography (they first worked together when Muhly was sent to conduct Millepied’s ballet version of Glass’s Einstein on the Beach in Paris). “For me, my relationship to my body is like meeting a long-distance relative,” says Muhly. “Like, I recognize I’m related to this thing I carry around with me, but I don’t necessarily know how to speak to it. And for dancers it’s so immediate.” Ballet, he says, “was always one of those things I’d wanted to do, but it just always seemed too complicated.”

That anything could seem complicated to Muhly is a little surprising. While he juggles the ballet, a commission for the Chicago Symphony (“I’m flying in and out in one day for rehearsal in the middle of the ABT run””crazytown!”), a nascent film score (for Kenneth Lonergan’s Margaret), and his own project Mothertongue (consisting simply of voice loops of a friend singing the alphabet, addresses, and other mundanities), there’s also Muhly’s main career offshoot: giving advice to nonclassical indie artists. “Bad string arrangements in rock music are a blight on all of our ears,” he deadpans. “It doesn’t take long to do it right””it just takes knowing how notes are related to each other. There’s a sense in the pop-rock world, “˜You don’t need to go to conservatory, you don’t need to go to school!’ But if you listen to a really great arrangement, chances are it’s been done by someone who knows how to space something.”

That someone is, often, Muhly (see the “special thanks” on several tracks of Rufus Wainwright’s Release the Stars), but frankly he’d rather hear a bit less about it. “With Björk, I played the piano and helped her realize some ideas. To a certain extent, what more can I say?”

Making good pop means pleasing someone other than yourself, which sets Muhly apart from a few conservatory colleagues. “You know, in the classical-music world, to even admit that you want people to like what you do is this really vile taboo. There’s, like, a Molotov cocktail coming through the window right now!” He freely admits he’s not entirely enamored of the composer community. “Composers who argue about capital-S style””I kinda don’t want to be involved in it,” he says, adding that whether a composer is “uptown” or “downtown” matters very little when style is innate in the first place. “The way I think about style is, you’re basically acting on things that are not under your control. But there are people who don’t acknowledge they have this crazy-ass life story,” he explains. “And then there are people who all they want to talk about is their diversity of experience, and it’s like, Can you just live in the moment for a second?!” He pauses. “Style is a lot like ethnicity. You really don’t have a choice, so you’d better rock it out!”

Although Muhly must still contend with the usual criticisms of young composers””the devil word derivative, for instance, thanks to his association with minimalist forefather Glass””this ballet could showcase a more mature ability to blend his own style with someone else’s. “I knew Benjamin had a huge love for Bach,” he explains. “So when the opportunity came up to work together, I thought, This boy needs a repetitive bass line, if I know one thing about this piece!” That line is indeed the crux of the 25-minute piece, overlaid with signature Nico touches: effervescent flourishes (“sparkles,” as he often calls them with a wave of the hands), moody string lines adding intrigue, brief cacophonies of trumpets. It’s a mix of his primary influences””the radiant harmonies of early-music masters (like Byrd and Tallis) and the slow build of minimalism (Steve Reich and John Adams”””the stuff I had a very serious teenage emotional connection to”). Pulsing through the whole thing is Muhly’s own alternately aggressive and pristine energy.

There’s about a month to go before the premiere of From Here on Out, and Muhly is watching a rehearsal of the pas de trois at the ABT studio downtown, quite close to his own space within his mentor’s Looking Glass Studios. (He won’t be leaving Glass’s employ anytime soon”””I have this job, ostensibly,” in which he helps out when needed, gets health insurance, and has ample time for his own work.) In signature Nico fashion, he first pranced into ABT with a Perrier for Millepied (“It’s your nutrients!”), but now he’s grown quiet, marveling as Millepied directs the dancers. He’s collaborator turned spectator, at least for the moment. Watching these dancers, like making classical music, is an “opportunity to break out of your biography a bit.”

Muhly is one of those rare young artists who can get away with suggesting that he’s outgrown youth””that the prodigy label might want to be retired about now. “There’s been a difference lately between my age being the first thing people say to its being the second or third,” he says. “I know how old I am. The process of writing music is the same, the work is the same. But people used to be listening for the reason of “˜It’s freakish that young people can come up with these ideas!’ Maybe now people will actually just listen.”